U.S. patent number 6,776,165 [Application Number 10/242,389] was granted by the patent office on 2004-08-17 for magnetic navigation system for diagnosis, biopsy and drug delivery vehicles.
This patent grant is currently assigned to The Regents of the University of California. Invention is credited to Sungho Jin.
United States Patent |
6,776,165 |
Jin |
August 17, 2004 |
Magnetic navigation system for diagnosis, biopsy and drug delivery
vehicles
Abstract
This invention discloses such a convenient navigation system and
navigatable capsules which are useful for remote-controlled
imaging, biopsy and programmable drug release within the body of an
animal. The components of the system comprise a capsule dimensioned
and shaped to move within the body. An anisotropic magnetic
component is mechanically coupled to the capsule to move or orient
the body in relation to an applied magnetic field, and a magnetic
field generating system external of the body generates a three
dimensionally oriented magnetic field within the body to move or
orient capsule.
Inventors: |
Jin; Sungho (San Diego,
CA) |
Assignee: |
The Regents of the University of
California (San Diego, CA)
|
Family
ID: |
31991396 |
Appl.
No.: |
10/242,389 |
Filed: |
September 12, 2002 |
Current U.S.
Class: |
128/899;
600/424 |
Current CPC
Class: |
A61B
1/00158 (20130101); A61B 1/041 (20130101); A61B
34/73 (20160201); A61B 34/70 (20160201); A61B
2562/028 (20130101); A61B 90/361 (20160201) |
Current International
Class: |
A61B
19/00 (20060101); A61B 1/04 (20060101); A61B
019/00 (); A61B 005/05 () |
Field of
Search: |
;600/114,117,407,109,101,587,424,300,474,486,426,582,302,549,578,106
;324/507.1 ;606/41,130 ;128/899,903 ;396/17,183 ;348/77,76,92
;455/100,67.11,67.13,95 ;604/113,890.1,891.1,131,327,93.01,244
;424/426 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jones; Mary Beth
Assistant Examiner: Veniaminov; Nikita R
Attorney, Agent or Firm: Lowenstein Sandler PC
Claims
What is claimed is:
1. A system for moving a capsule within the body of an animal
comprising: a capsule dimensioned and shaped to move within the
body of the animal; mechanically coupled to the capsule, an
anisotropic magnetic component to orient the capsule in relation to
an applied magnetic field; a detector to determine the location of
the capsule within the body; and a magnetic field generating system
external of the body responsive to the detected location of the
capsule for generating a three dimensionally oriented field within
the body to move the anisotropic magnetic component and thereby the
capsule within the body.
2. The system of claim 1 wherein the detector senses the position
of the capsule and the feedback of the position information at
every moment is utilized for controlling the magnetic field
generating system to guide the capsule.
3. The system of claim 1 wherein the detector senses sidewall
pressure and the feedback of the pressure information is utilized
by the magnetic field generating system to minimize the pressure
exerted by the capsule on the wall of the tract duct or cavity.
4. The system of claim 1 wherein the capsule is dimensioned and
shaped to move within the gastro-intestinal tract of an animal.
5. The system of claim 1 wherein the capsule includes an imaging
device.
6. The system of claim 1 wherein the capsule includes a biopsy
device.
7. The system of claim 6 wherein the biopsy device is remotely
controllable.
8. The system of claim 1 wherein the capsule includes a drug
release device.
9. The system of claim 8 wherein the drug release device is
remotely controllable.
10. The system of claim 1 wherein the capsule includes a source or
detector of ultrasonic energy.
11. The system of claim 10 wherein the source or detector of
ultrasonic energy is remotely actuable.
12. The system of claim 1 wherein the capsule includes a source or
detector of thermal energy.
13. The system of claim 12 wherein the source or detector of
thermal energy is remotely actuable.
14. The system of claim 1 wherein the capsule includes a source or
detector of mechanical vibration.
15. The system of claim 1 wherein the source or detector of
mechanical vibration is remotely actuable.
Description
FIELD OF INVENTION
This invention relates to bioengineering systems, and in
particular, to a magnetic navigation system for moving a device
within the body of an animal such as a human being. The system is
particularly useful within tracts, ducts or cavities such as the
gastrointestinal (GI) tract.
BACKGROUND OF INVENTION
Various diagnostic techniques are used for detection of tumors,
ulcers, and other abnormal conditions in the body. These techniques
include x-ray imaging, ultrasonic testing, MRI, endoscopy,
sigmoidoscopy and colonoscopy. Recently, a camera-in-a-capsule
device has been developed and reported, see U.S. Pat. No.
5,604,531, "In vivo video camera system" issued to Iddan et al. on
Feb. 18, 1997 and U.S. Pat. No. 6,428,469, "Energy management of a
video capsule" issued to Iddan et al. on Aug. 6, 2002. Recent FDA
approval (August, 2001) of an ingestible camera developed by Given
Imaging Ltd. and tested at New York Mount Sinai Hospital received
considerable news media attention. Such a device is schematically
illustrated in FIGS. 1 and 2.
Referring to FIGS. 1 and 2, the ingestible camera 10 is a
finger-tip sized capsule 11 containing a camera composed of lens
12, an image detector 13 and one or more light sources 14. A
wireless transmitter 15 (including antenna) is provided for video
signal transmission. The capsule also includes, batteries 16, and
circuit chips (not shown). When a patient swallows the capsule, the
natural muscular waves of the digestive tract propel it downward;
and, as it goes down, the camera takes pictures of the small
intestine wall for video transmission to detect tumors, ulcers, or
causes of bleeding. This procedure permits the diagnosis of the
small intestine, which is difficult to access by colonoscopy. For
larger regions, such as the stomach or the large intestine, this
type of non-guided camera tends to lose orientation and reliable
imaging covering all surface areas is no longer be possible. It
would be desirable if the position of the camera could be
controlled so that no portion of the GI tract surface would be
missed.
The most common therapy for treatment of GI tract problems with
drugs is oral administration, rather than a concentrated
application of the drugs directly on the affected area. Such a
practice results in inefficient use of drugs, and is often
accompanied by unwanted side-effects, with restrictions in the use
of more potent treatment doses, especially in the treatment of
tumors. It would be highly desirable if the drug release can be
programmed so that the exact desired doses can be applied directly
at a time at a specific location in the GI tract (e.g., on or near
a tumor). Accordingly there is a need for a system to direct the
movement and orientation of diagnosis and treatment vehicles within
animal bodies.
SUMMARY OF THE INVENTION
This invention discloses such a convenient navigation system and
navigatable capsules which are useful for remote-controlled
imaging, biopsy and programmable drug release within the body of an
animal. The components of the system comprise a capsule dimensioned
and shaped to move within the body. An anisotropic magnetic
component is mechanically coupled to the capsule to move or orient
the body in relation to an applied magnetic field, and a magnetic
field generating system external of the body generates a three
dimensionally oriented magnetic field within the body to move or
orient capsule.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature, advantages and various additional features of the
invention will appear more fully upon consideration of the
illustrative embodiments now to be described in detail with the
accompanying drawings. In the drawings:
FIG. 1, which is prior art, depicts a swallowable camera;
FIG. 2, which is prior art, schematically illustrates the
components of the FIG. 1 device;
FIG. 3 schematically illustrates an exemplary navigatable
biocapsule device and navigation control system according to the
invention.
FIGS. 4(a) and (b) schematically illustrate exemplary magnetically
navigatable biopsy MEMS devices according to the invention.
FIG. 5 schematically illustrates an exemplary use of navigatable,
programmable, and remote-releasable drug release MEMS capsule
according to the invention.
It is to be understood that the drawings are for purposes of
illustrating the concepts of the invention and are not to
scale.
DETAILED DESCRIPTION OF THE INVENTION
In order to solve the operation difficulties and limitations
associated with non-guided drug release capsules or diagnostic
capsules, a new, remote-controlled, magnetic navigation system is
provided to efficiently guide diagnostic or medication capsules
within the body and perform diagnostic, biopsy or programmable drug
release. Within the GI tract, the navigatable capsules override the
time limit imposed by the naturally occurring muscular movement of
the tract, thus allowing repeated medication therapy on one or more
affected areas over an extended period of time.
FIG. 3 schematically illustrates a system 30 for moving a capsule
31 within the body of an animal 32 to accomplish magnetic
navigation of the capsule 31, one or more soft magnetic, semi-hard
magnetic, or permanent magnetic component is mechanically coupled
to the capsule, e.g. embedded inside the capsule or attached onto
the surface. In the case of surface-mounted magnetic component, it
is preferably coated with biocompatible, clinically safe material
(not shown) such as, for example, diamond, a bio-compatible
polymer, titanium, or stainless steel. A magnetic component 33
should be anisotropic either in magnetic properties or in shape to
orient the capsule in relation a magnetic field applied by
electromagnets 34. The shape of the magnetic component should be
elongated along the length direction of the capsule to provide
magnetic shape anisotropy or the component can comprise a material
with high magneto-crystalline anisotropy along the length
direction. In the presence of three-dimensional guiding field, the
anisotropy aligns the capsule along the direction of the applied
field. By slowly altering the applied field direction following the
contour of a tract or duct, the capsule can be guided along the
tract or duct, e.g. along the GI tract. A three-dimensional,
programmable magnetic field system made up of a series of
electromagnets, superconducting magnets, or movable permanent
magnets, can externally generate a guiding magnetic field within
the body. Each electromagnet 34 can be separately controlled by a
processor 35 to establish a field of desired magnitude, orientation
and gradient in the region of capsule 31.
Movement of the magnetic object is induced if there is a magnetic
field gradient near the magnetic object. A programmable or
sequential change of electromagnets 34 can provide a magnetic field
strength and gradient near the magnetically tagged capsule to guide
and move the capsule at a programmed speed. The capsule 31 is
dimensioned and shaped to move within a tract, duct or cavity of
the body.
The exemplary capsule 31 shown as a camera for video imaging.
However, the present invention also includes other navigatable
devices such as a biopsy device, a drug release device, or a
diagnostic or treatment device, or any combination of these. The
navigatable diagnostic and/or theraputic treatment devices can
include, for example, a local ultrasonic wave source and/or
detector for localized acoustic diagnosis or treatment (e.g., to
damage or disrupt unwanted cell structure), a localized x-ray
source and/or detector, a source of intense heat radiation to
disrupt or damage tumor growth, or a mechanical vibration source
and/or detector to stimulate or slow down cell growth.
While the gradient along the GI tract direction needs to be
maximized for capsule movement, the gradient along the
perpendicular directions should be balanced to prevent undue
pressure on the GI tract wall. An array of bio-compatible pressure
sensors (not shown) can be embedded on the capsule surface so that
the sensed pressure information is transmitted as a feedback to the
programmable 3-D field generation system. In response to the
pressure signals the magnetic field distribution can be
automatically adjusted to eliminate the sideways pressure.
The position of the capsule 31, if needed to be traced in real
time, may be detected by a number of different tracking techniques.
For example, magnetic interrogation (magnetic position sensing),
ultrasound imaging, or CT scan may be utilized. Feedback to the 3-D
field generation system can be used to obtain desired movement.
Recent advances in MEMS (Micro-Electro-Mechanical-systems)
technology now permit fabrication of very minute machines capable
of complex motions and maneuvers. A bioMEMS device can be
incorporated into the magnetically navigatable capsule to perform
tissue sampling (e.g., for biopsy of polyps, tumor cells) or body
fluid sampling in the tract, duct or cavity. Such a device is
schematically illustrated in FIG. 4A. A pop-up instrument 40
collects the tissue sample and then retracts into the capsule with
a door closing behind. Such a command for biopsy action can be
relayed to the MEMS capsule by remote magnetic signals or wireless
RF signals. Alternatively, a fluid sample door can be opened and
closed upon command.
The MEMS capsule can also be made with a drug release compartment
41 to store and programmably release desired medications (FIG. 4B)
such as chemotherapy drugs or antibiotics as schematically
illustrated in FIG. 5, a drug delivery capsule 51 can controllably
release directly on a problem area 52. The magnetically navigatable
system enables the capsule to stay at a fixed location and release
medication repeatedly over extended period, for example, every 4
hours. If there are two tumors to be treated, the capsule can go
back and forth and release the drug on both areas repeatedly. If a
mix of drugs is to be administered, a MEMS capsule with a
multi-compartment structure will be commanded to do so via remote
signals. The programmable drug release device, according to the
invention, contains remote-activatable valves and other actuation
mechanisms which can be activated by either magnetic means or by
FM/microwave signals (if the use of magnetic actuation is
undesirable or is to be minimized). For example, an
activation/operation of remote magnetic release of valves in the
drug release capsule may be affected by the presence of navigating
magnetic field unless the navigating field is temporarily turned
off for short time drug release. In case of prolonged holding of
the navigating capsule in place by magnetic field, the field can
not be turned off during the intended period.
The capsule can be powered with a battery, for example, typically
with several hours life. Alternatively, the system can be provided
with an AC magnetic field source (e.g. 60 Hz) and the navigating
biocapsule can be equipped with a transducer device for receiving
energy through the external AC magnetic field. Using a magnetic AC
induction coupling, a transformer solenoid in the capsule can
receive power from outside, and then convert the AC power to DC
power and store the energy in the battery or a capacitor. This
embodiment indefinitely extends the battery life, and the useful
life of the device.
In summary, it can now be seen that the invention includes a system
for moving a capsule within the body of an animal. (The term animal
as used herein is intended to include human beings). The components
of the system comprise a capsule dimensioned and shaped to move
within the body of the animal. An anisotropic magnetic component is
mechanically coupled to the capsule to move or orient the capsule
in relation to an applied magnetic field, and a magnetic field
generating system external of the body is provided for generating a
three dimensionally oriented magnetic field within the body to move
or orient the capsule. Advantageously the capsule has an outer
surface of biologically compatible (biocompatible) material. And in
a preferred embodiment the system includes a detector for
determining the location or orientation of the capsule within the
body. The detector can be selected, for example, from devices
utilizing a number of different techniques such as x-ray analysis,
ultrasonic sensing, magnetic position sensing. The programmable
magnetic field generator can then respond to the detected location
of the capsule to orient the capsule at a desired orientation for
the detected location. The position of the capsule can be
continuously detected, and the feedback of the position information
can be used to control the magnetic navigation system in guiding or
moving the capsule. The pressure on the sidewalls of the capsule
can be continuously detected by sensors on the capsule, and the
feedback of the pressure information can be used to control the
system to minimize pressure on the wall of the tract, duct or
cavity.
In advantageous embodiments, the capsule can be dimensioned and
shaped for moving in a tract, duct or cavity of the body, e.g. an
elongated capsule is convenient for moving in the gastro-intestinal
tract. It can include an imaging device, a biopsy device, a drug
release device or a source or detector of ultrasonic energy,
thermal energy or mechanical vibration for treatment or diagnosis.
A spherically symmetrical capsule may be advantageous in cavities,
and smaller capsules are preferred for smaller tracts and ducts.
The sources can be remotely (externally) actuable. In addition, the
capsule can be provided with a transducer for extracting energy
from an externally generated AC magnetic field.
It is understood that the above-described embodiments are
illustrative of only a few of the many possible specific
embodiments, which can represent applications of the invention.
Numerous and varied other arrangements can be made by those skilled
in the art without departing from the spirit and scope of the
invention.
* * * * *